When I need to decommission a hard drive, it's necessary for me to to securely wipe the data prior to disposal. Stanford's data wiping policy is publicly accessible from the internet (though woefully out of date with the product recommendations—Mac OS 8 anyone?). It's usually not enough just to delete the files using the Finder or the rm command, since that action merely hides your files and makes their blocks eligible for possible future write-overs. Inexpensive file recovery software can usually return data when you simply delete files this way, to say nothing of real forensics software.
Continue reading diskutil command line secureErase options.
